From 6742f30d9cf1960cf1eb96ef248c59615386b00b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stephan=20B=C3=B6sch-Plepelits?= <skunk@xover.mud.at>
Date: Sun, 15 Jul 2018 22:39:25 +0200
Subject: [PATCH] Twig: new filters 'natsort' and 'unique'

---
 doc/TwigJS.md        |  2 ++
 package.json         |  1 +
 src/twigFunctions.js | 11 +++++++++++
 3 files changed, 14 insertions(+)

diff --git a/doc/TwigJS.md b/doc/TwigJS.md
index 2a86392b..6dd4b19c 100644
--- a/doc/TwigJS.md
+++ b/doc/TwigJS.md
@@ -65,6 +65,8 @@ Extra filters:
 * filter websiteUrl: return a valid http link. Example: `{{ "www.google.com"|websiteUrl }}` -> "http://www.google.com"; `{{ "https://google.com"|websiteUrl }}` -> "https://google.com"
 * filter `matches`: regular expression match. e.g. `{{ "test"|matches("e(st)$") }}` returns `[ "est", "st" ]`. Returns null if it does not match.
 * filter `osmDateParse`: returns an array with the lower and upper boundary of the year of a `start_date` tag. See [https://github.com/plepe/openstreetmap-date-parser](openstreetmap-date-parser) for details.
+* filter `natsort`: Sort an array naturally, see [https://www.npmjs.com/package/natsort](natsort) for details.
+* filter `unique`: Remove duplicate elements from an array.
 
 Notes:
 * Variables will automatically be HTML escaped, if not the filter raw is used, e.g.: {{ tags.name|raw }}
diff --git a/package.json b/package.json
index fb08b677..1df6530e 100644
--- a/package.json
+++ b/package.json
@@ -23,6 +23,7 @@
     "leaflet.polylinemeasure": "https://github.com/ppete2/Leaflet.PolylineMeasure.git",
     "modulekit-tabs": "^0.1.0",
     "moment": "^2.18.1",
+    "natsort": "^1.0.6",
     "opening_hours": "^3.5.0",
     "openstreetbrowser-categories-main": "https://github.com/plepe/openstreetbrowser-categories-main",
     "openstreetmap-date-parser": "^0.1.0",
diff --git a/src/twigFunctions.js b/src/twigFunctions.js
index 8cea8dd5..134091cd 100644
--- a/src/twigFunctions.js
+++ b/src/twigFunctions.js
@@ -2,6 +2,7 @@ var OverpassLayer = require('overpass-layer')
 var OpeningHours = require('opening_hours')
 var colorInterpolate = require('color-interpolate')
 var osmParseDate = require('openstreetmap-date-parser')
+const natsort = require('natsort')
 
 OverpassLayer.twig.extendFunction('tagsPrefix', function (tags, prefix) {
   var ret = {}
@@ -41,6 +42,16 @@ OverpassLayer.twig.extendFilter('websiteUrl', function (value) {
 OverpassLayer.twig.extendFilter('matches', function (value, match) {
   return value.toString().match(match)
 })
+OverpassLayer.twig.extendFilter('natsort', function (values, options) {
+  return values.sort(natsort(options))
+})
+OverpassLayer.twig.extendFilter('unique', function (values, options) {
+  // source: https://stackoverflow.com/a/14438954
+  function onlyUnique(value, index, self) {
+    return self.indexOf(value) === index
+  }
+  return values.filter(onlyUnique)
+})
 OverpassLayer.twig.extendFunction('colorInterpolate', function (map, value) {
   var colormap = colorInterpolate(map)
   return colormap(value)